Monomer cylinder derived carbon nitride aerogel for flow photosynthesis of hydrogen peroxide

Flow photocatalysis represents a cutting-edge technology that could simultaneously achieve fast mass transfer and product separation. The robust carbon nitride aerogel (CN(AG)) holds great promise in conventional photocatalysis as well as in flow photocatalysis due to its high accessible surface area and dimensional integrity. Herein, we developed a facile synthesis of CN(AG) derived from monomer cylinder by dimension-retained thermal condensation for photosynthesis of H₂O₂. The obtained CN(AG) delivered 3.74-times higher H₂O₂ yield by its powder form than common CN in ethanol aqueous solution, reaching 13.66 mmol/g/h with AQY of 15.2 % at 400 nm. While for the bulk CN(AG) cylinder, it demonstrated excellent static and flow H₂O₂ photosynthesis performances with yields of 10.8 mmol/m²/h and 4.8 mmol/m²/h, respectively. The applications of the photosynthesized H₂O₂ were exemplified by the fast photocatalytic degradation of tetracycline hydrochloride and efficient disinfection of E. coli, as well as excellent photocatalytic regeneration ability after high dye adsorption. Mechanism study revealed the two-step 1e⁻ photocatalytic oxygen reduction pathway. This work demonstrated efficient photosynthesis of H₂O₂ and environmental remediation by a robust CN aerogel and would inspire many other energy/environment related applications.